Method of constructing tunnels



`luly 18, 1933. ,C, MEEM METHOD oF coNsTRucTnm TUNNELS Filed June 23, 1931 INVENTOR joa/MM /C. Wfl/Lawn,

BY r

ATTORNEYS improved method of constructing tunnel 'ap- Patented Jeiy is, 1933 JAMES c. ME'EM, on BnooKLYN, ivnw YORK' MET-Honor ooivsrnncmme "rUNNnns l Application led June 23, i

v My :invention relates to tunnels, and particularly tomethods of ,constructing ,ap- -proachtrenches and'approach tunnels associated withunderwater, tunnels. The general object of the invention is to :provide Van `]g roaches to underwater tunnels, comprising.

f methods of sheeting, bracing and excavating closures, towing these to vposition over cover Vmethods employed iii "building the s Y approach trenches and laying submersible approach tunnels or tunnel sections therein, and 'which have advantages' over methods heretofore employed in such cases where approaches havel been built by ordinary kcompressed air methods or by open cutand.cover methods. Y

To therabove ends my invention consists in features of construction and arrangements hereinafter describedand particularlypointed outrin the claims. Y v

The invention ,is especially useful when employed `in constructing approaches to tun` nels built in open trenches under rivers-or other bodies of water, the approach tunnels being under riparian landsor streets adjacent tothe main water body. .l have heretofore designed and utilized certain vimproved methods of constructing and laying tunnelsections in such main water bodies which involve separately constructing the sections with end dredged trenches, and sinking them.v under suitable control toposition in the trench, the sections being subsequently joined endtoendand opened to provide acontinuous passageway through the sections constituting the tunnel.

By my present invention approachvtunnel sections may be employed of thesame generaltype as those constituting the main bodyV of the tunnel, with resulting advantages'in economy, safety, and` speed Ain comparison with the usual compressed air or cut-andapproaches.

'An exemplilication of the present invention will be described andexplained in connection with the accompanying drawing, wherein v Fig. 1 is a transverse sectional view of an trench. 1 v

1931'. l serial no. Maico.Y j

position therein;

Iapproachtrench,l with; a" tunnel `sectionrin i IF ig. 2 vis a fragmeiitary'plan viewfof the l;

trench with abutting ,tunnel sections; f

Fig. 3 is a fragmentary longitudinal sec- Y tional viewgofthe trench and abutting tunnel sections, ,and v Fig. 4 isa fragmentary enlarged plan view of the -side walll lof the trench.

In carryingoutiny method I irst drive at intervals along theoutside lines or margins of theV proposed trench, bracing units or .master 4piles generally ydesignated as ,10,the

space between'thelines of themaster piles and defining the ,sides of the trench being of appropriate VWidth.A

65 l Each master pileiis preferably.constitutednof ka metallicL (rolled. y beam-11, suchvas anfbeam or l-i-beam, tothe back or outside marginal portionsof which :'70

are secured as byfriveting, sections vl2 of steel sheet-piling of suitablek type, .the outeredgev portions of which areprovidedwith. interlocking devices 12a; and 12b. :Thefmaster piles are driven atintervals of fteengfeet moreor less and are of alength sufficient to :extendfrom .al few.v feet above thelevelof the water in the trench to be excavated,

. the series being interlockedlwith Vthe linterlockingsections i2., thus closing the gaps'jor spaces betweenthe'master lpiles. Ordinarily in drivingthe series of pilesg between two .masterpile units, the end piles of lthe'Sofie-S, .that isthose connected to' they lsections 12,'willfbe drivenfirst, followed by'. lthe nextin order,

associate pile the last two orthreef piles .through the earth aV distance of from ten to i in the middle of the series being interloeled and driventogether. Instead ofl being driven` .inffa straightline betweenithe masterpiles, each :series ofpilestl?) between two of the ma'sf tter-pilesfarein `theform ofvanarc with vits convexity inward. Such arc in effect maya be :said to be' horizontally suspended atits ends,

. the points ofsuspensionbeing-the master 1 piles 1,0. ,The trench walls proper having beengthus completed, next,l horizontal braces 14 are connected to the upper portion of each pair of master piles disposed at the opposite margins of the trench, the cross braces being preferably heavy metallic rolled beams which may rest onv and be secured Vto angle plates 14a which are fixed to the master piles. The cross braces preferably are disposed so as to afford some live feet of clearance above the low water level. Uponcompletion of the piling operation and the bracing, the'trenchl between the lines or walls of piling is dredged., or excavated, but without being dewatered.

If required, bearing pilesl 15 -may then be driven and cut off to the grade line 15a of the bottom of the trench. y y

The present method of constructing an approach trench is particularly adapted for use with tunnels-constituted by submersible sections which are-towed to position in the water over the trench andbetweenits walls of piling, and thereafter sunk and connected;

and inthe drawing there are shown tunnel sections 16 of'this Vgeneral type, provided with end closures or diaphragms 17. As herein illustrated, these sections are provided with temporary buoyant shafts 18 near their ends, these shafts being applied after the sections have been towed to position and preliminary to sinking. Underlying the shaft seats 18a arebulk-headed spaces or flooding cham- -bers 19. This construction enables the tunf theretofore emplaced.

'nel sections to be submerged to prepared locatlons under suitable control.

When each section has been sunk` and brought to rest on` the bearing piles l5 itis adjusted to position and the end diaphragm 17 of one section pulled to contact with the abutting diaphragm'of the adjoining section The. shafts 18 are Ythen removed' and the shaft seats 18a closed orblocked. f Y

- v The trench'may be then back-filled, the tunnel sections 16 entered consecutively and the contacting diaphragms permanentlyconnected as by internal riveting, after which they Yare cut or-burned out along their inner peripheries insidethe connecting rivets and the connection completed. These submerged conanected sections, it will beunderstood, constitute the shell of the completed approach tunnel which is suitably7 lined as indicated at 20. Whilethe method of constructing the trench isv particularly adapted for use with a submersible tunnel of the general type described,

.it is to be understood that in principleits use is not'so restricted. Y

It is ,to be observed that where there is a j considerable overfburden of earth, this may be excavated and braced by. ordinary methods until the water level is reached, after which my improved method is to be employed.

When feasible the sheet piling may be pulled up and used again or salvaged. y

It is `further to be `understood thatva'riations in detail may be employed without departing from the scope of the invention.

l. The method of preparing an approach trench'for the approach portions of underf water tunnels which comprises driving unitary breast members at intervals along the side' margins of the proposed trench, each kconstituted by a metallic beam with metallic sheet-pile sections, driving connected metallic sheet piles' between 'and connected to said unitary members, connecting cross braces to opposite unitary'members, and dredging or excavating between the trench walls lthus formed. v

2. The method of preparing an approach trench for an approach portion of an under- Vwater-,tunnel which .comprises driving unitary breast members at regularly spaced intervals along theside marginsl of the proposed trench, suchA breast members constituted-byv a metallic beam and connected metallic sheet pile sections, driving metallic sheet'pilesin an arcuate line between each pair of adjacent unitary breast members, the (au `breast members and sheet piles being connected and constituting in effect an inwardly Vcurved iexible arc inihorizontal cross section withthe said adjacent unitary members asits points of suspension, and then connectinglua' bracing members across the trench to opposite unitary members.

3. The method of preparing an approach trench for the approach portion of an undery water tunnel which comprises drivingunifiti. tary master piles-at intervals along the side margins ofthe proposed trench, each master pile constituted by a metallicbeam with rigidly connected sheet pile sections at itsv side edge portions, driving connected metallic sheet Apiles connected to vsaid unitary members, then connect-ing cross braces to the upper Vportions of the master pile above the water line, and then dredging or excavating Abe-, tween the'trench walls thus formed, all with-"le out dewatering.

- l.- The method of preparing an approachtrenchfor the approach portion of an underwater tunnel, which comprises defining, as by, Y walls of sheet piling, a trench for receivingrl submersible tunnel sections, next excavating the material between the walls thus defined Y without dewatering the trench, and next bracmaster piles so that the pressure of the soil- Without the trench lines is transferred in have been rigidily attached to extend lateri horizontal tension, then applying cross bracing to the tops of-"opposite master piles above f l the Water lines so as to leave the space below free and clear, and then dredging out the material k:it the bottom of the ytrench to the,

required depth Without devvatering. n

i JAMES o MEEM. 

